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HIF-2α
Endothelial PAS domain-containing protein 1 (EPAS1, also known as hypoxia-inducible factor-2alpha (HIF-2α)) is a protein that is encoded by the ''EPAS1'' gene in mammals. It is a type of hypoxia-inducible factors, hypoxia-inducible factor, a group of transcription factors involved in the physiological response to oxygen concentration. The gene is active under Hypoxia (environmental), hypoxic conditions. It is also important in the development of the heart, and for maintaining the catecholamine balance required for protection of the heart. Mutation often leads to Neuroendocrine tumor, neuroendocrine tumors. However, several characterized allele, alleles of ''EPAS1'' contribute to high-altitude adaptation in humans. One such allele, which has been inherited from Denisovan archaic humans, archaic hominins, is known to confer increased athletic performance in some people, and has therefore been referred to as the "super athlete gene". Function The EPAS1 gene encodes one subunit o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypoxia-inducible Factors
Hypoxia-inducible factors (HIFs) are transcription factors that respond to decreases in available oxygen in the cellular environment, or hypoxia. They also respond to instances of pseudohypoxia, such as thiamine deficiency. Both hypoxia and pseudohypoxia leads to impairment of adenosine triphosphate (ATP) production by the mitochondria. Discovery The HIF transcriptional complex was discovered in 1995 by Gregg L. Semenza and postdoctoral fellow Guang Wang. In 2016, William Kaelin Jr., Peter J. Ratcliffe and Gregg L. Semenza were presented the Lasker Award for their work in elucidating the role of HIF-1 in oxygen sensing and its role in surviving low oxygen conditions. In 2019, the same three individuals were jointly awarded the Nobel Prize in Physiology or Medicine for their work in elucidating how HIF senses and adapts cellular response to oxygen availability. Structure Oxygen-breathing species express the highly conserved transcriptional complex HIF-1, which is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High-altitude Adaptation In Humans
High-altitude adaptation in humans is an instance of evolutionary modification in certain human populations, including those of Tibet in Asia, the Andes of the Americas, and Ethiopia in Africa, who have evolved the ability to survive at altitudes above 2,500 meters (8,200 ft). This adaptation means irreversible, long-term physiological responses to high-altitude environments associated with heritable behavioral and genetic changes. While the rest of the human population would suffer serious health consequences at high altitudes, the indigenous inhabitants of these regions thrive in the highest parts of the world. These humans have undergone extensive physiological and genetic changes, particularly in the regulatory systems of oxygen respiration and blood circulation when compared to the general lowland population. Around 81.6 million humans (approximately 1.1% of the world's human population) live permanently at altitudes above 2,500 meters (8,200 ft), which would seem to put ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metabolic reactions, DNA replication, Cell signaling, responding to stimuli, providing Cytoskeleton, structure to cells and Fibrous protein, organisms, and Intracellular transport, transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the Nucleic acid sequence, nucleotide sequence of their genes, and which usually results in protein folding into a specific Protein structure, 3D structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20–30 residues, are rarely considered to be proteins and are commonly called pep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heart Failure
Heart failure (HF), also known as congestive heart failure (CHF), is a syndrome caused by an impairment in the heart's ability to Cardiac cycle, fill with and pump blood. Although symptoms vary based on which side of the heart is affected, HF typically presents with shortness of breath, Fatigue (medical), excessive fatigue, and bilateral peripheral edema, leg swelling. The severity of the heart failure is mainly decided based on ejection fraction and also measured by the severity of symptoms. Other conditions that have symptoms similar to heart failure include obesity, kidney failure, liver disease, anemia, and thyroid disease. Common causes of heart failure include coronary artery disease, heart attack, hypertension, high blood pressure, atrial fibrillation, valvular heart disease, alcohol use disorder, excessive alcohol consumption, infection, and cardiomyopathy. These cause heart failure by altering the structure or the function of the heart or in some cases both. There are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ghost Population
A ghost population is a population that has been inferred through using statistical techniques. Population studies In 2004, it was proposed that maximum likelihood or Bayesian approaches that estimate the migration rates and population sizes using coalescent theory can use datasets which contain a population that has no data. This is referred to as a "ghost population". The manipulation allows exploration in the effects of missing populations on the estimation of population sizes and migration rates between two specific populations. The biases of the inferred population parameters depend on the magnitude of the migration rate from the unknown populations. The technique for deriving ghost populations attracted criticism because ghost populations were the result of statistical models, along with their limitations. Population genetics Humans In 2012, DNA analysis and statistical techniques were used to infer that a now-extinct human population in northern Eurasia had interbred with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tibetan Mastiff
The Tibetan Mastiff is a large Tibetan dog breeds, Tibetan dog breed. Its double coat is medium to long, subject to climate, and found in a wide variety of colors, including solid black, black and tan, various shades of red (from pale gold to deep red) and bluish-gray (dilute black), and sometimes with white markings around its neck, chest and legs. According to the American Kennel Club, male Tibetan Mastiffs have a weight of 40-70 kg (90-150 lbs) while females are 30-55 kg (70-120 lbs). Name The term ''mastiff'' was assigned by the Europeans who first came to Tibet because that name was used to refer to nearly all large dog breeds in the West. Early Western visitors to Tibet misnamed several of its breeds, such as the Tibetan Terrier, Tibetan terrier, which is not a terrier, and the Tibetan Spaniel, Tibetan spaniel, which is not a spaniel. A better name for the breed might be the ''Tibetan mountain dog'' or—to encompass the landrace breed throughout its range—the ''Himalaya ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Himalayan Wolf
The Himalayan wolf (''Canis lupus chanco'') is a Canis, canine of debated taxonomy. It is distinguished by its genetic markers, with mitochondrial DNA indicating that it is genetically Basal (phylogenetics), basal to the Holarctic Wolf, grey wolf, genetically the same wolf as the Tibetan and Mongolian wolf, and has an association with the African wolf (''Canis lupaster''). No striking morphological differences are seen between the wolves from the Himalayas and those from Tibet. The Himalayan wolf lineage can be found living in Ladakh in the Himalayas, the Tibetan Plateau, and the mountains of Central Asia predominantly above in elevation because it has adapted to a low-oxygen environment, compared with other wolves that are found only at lower elevations. Some authors have proposed the reclassification of this lineage as a separate species. In 2019, a workshop hosted by the IUCN/SSC Canid Specialist Group noted that the Himalayan wolf's distribution included the Himalayan range a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archaic Human Admixture With Modern Humans
Interbreeding between archaic and modern humans occurred during the Middle Paleolithic and early Upper Paleolithic. The interbreeding happened in several independent events that included Neanderthals and Denisovans, as well as several unidentified hominins. In Europe, Asia and North Africa, interbreeding between archaic humans and modern humans took place several times. The introgression events into modern humans are estimated to have happened about 47,000–65,000 years ago with Neanderthals and about 44,000–54,000 years ago with Denisovans. Neanderthal-derived DNA has been found in the genomes of most contemporary populations, varying noticeably by region. It accounts for 1–4% of modern genomes for people outside Sub-Saharan Africa, although estimates vary, and either none or up to 0.3% for those in Sub-Saharan Africa. Cushitic and Semitic speaking populations from the Horn of Africa (such as Ethiopians), who derive a large portion of their ancestry from West Eurasian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tibetan People
Tibetans () are an East Asian people, East Asian ethnic group Indigenous peoples, native to Tibet. Their current population is estimated to be around 7.7 million. In addition to the majority living in the Tibet Autonomous Region of China, significant numbers of Tibetans live in the provinces of China, Chinese provinces of Gansu, Qinghai, Sichuan, and Yunnan, as well as in Bhutan, Tibetan refugees in India, India, and Nepal. The Tibetic languages belong to the Tibeto-Burman languages, Tibeto-Burman language group. The traditional or mythological explanation of the Tibetan people's origin is that they are the descendants of the human Pha Trelgen Changchup Sempa and rock ogress Ma Drag Sinmo. It is thought that most of the Tibeto-Burman speakers in southwest China, including Tibetans, are direct descendants from the Qiang (historical people), ancient Qiang people. Most Tibetans practice Tibetan Buddhism, although a significant minority observe the Indigenous Bon religion. There ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fetal Heart Rate
A fetus or foetus (; : fetuses, foetuses, rarely feti or foeti) is the unborn offspring of a viviparous animal that develops from an embryo. Following the embryonic stage, the fetal stage of development takes place. Prenatal development is a continuum, with no clear defining feature distinguishing an embryo from a fetus. However, in general a fetus is characterized by the presence of all the major body organs, though they will not yet be fully developed and functional, and some may not yet be situated in their final anatomical location. In human prenatal development, fetal development begins from the ninth week after fertilization (which is the eleventh week of gestational age) and continues until the birth of a newborn. Etymology The word ''fetus'' (plural ''fetuses'' or rarely, the solecism '' feti''''Oxford English Dictionary'', 2013''s.v.'' 'fetus') comes from Latin '' fētus'' 'offspring, bringing forth, hatching of young'. The Latin plural ''fetūs'' is not used in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cardiac Output
In cardiac physiology, cardiac output (CO), also known as heart output and often denoted by the symbols Q, \dot Q, or \dot Q_ , edited by Catherine E. Williamson, Phillip Bennett is the volumetric flow rate of the heart's pumping output: that is, the volume of blood being pumped by a single Ventricle (heart), ventricle of the heart, per unit time (usually measured per minute). Cardiac output (CO) is the product of the heart rate (HR), i.e. the number of heartbeats per minute (bpm), and the stroke volume (SV), which is the volume of blood pumped from the left ventricle per beat; thus giving the formula: :CO = HR \times SV Values for cardiac output are usually denoted as L/min. For a healthy individual weighing 70 kg, the cardiac output at rest averages about 5 L/min; assuming a heart rate of 70 beats/min, the stroke volume would be approximately 70 mL. Because cardiac output is related to the quantity of blood delivered to various parts of the body, it is an important com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fetal Heart
In humans, the circulatory system is different before and after birth. The fetal circulation is composed of the placenta, umbilical blood vessels encapsulated by the umbilical cord, heart and systemic blood vessels. A major difference between the fetal circulation and postnatal circulation is that the lungs are not used during the fetal stage resulting in the presence of shunts to move oxygenated blood and nutrients from the placenta to the fetal tissue. At birth, the start of breathing and the severance of the umbilical cord prompt various changes that quickly transform fetal circulation into postnatal circulation. Oxygenation, nutrient, and waste exchange Placenta The placenta functions as the exchange site of nutrients and wastes between the maternal and fetal circulation. Water, glucose, amino acids, vitamins, and inorganic salts freely diffuse across the placenta along with oxygen. Two umbilical arteries carry systemic arterial blood from the fetus to the placenta where w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
